Problem: Express your answer as a mixed number simplified to lowest terms. $3\dfrac{4}{7}+15\dfrac{1}{4} = {?}$
Separate the whole numbers from the fractional parts: $= {3} + {\dfrac{4}{7}} + {15} + {\dfrac{1}{4}}$ Bring the whole numbers together and the fractions together: $= {3} + {15} + {\dfrac{4}{7}} + {\dfrac{1}{4}}$ Add the whole numbers: $=18 + {\dfrac{4}{7}} + {\dfrac{1}{4}}$ Find a common denominator for the fractions: $= 18+\dfrac{16}{28}+\dfrac{7}{28}$ Add the fractions: $= 18+\dfrac{23}{28}$ Combine the whole and fractional parts into a mixed number: $= 18\dfrac{23}{28}$